With a gripping portion and at least one gripping surface which extends over at least a section of the gripping portion and which affords enhanced friction in comparison with the adjacent sections of the instrument.
In regard to surgical instruments such as tweezers or forceps, vessel dilators, clamping forceps, scissors or cutters, needle holders, arteriotomy clamps etc., a distinction is made between flat and round grip instruments; in a flat grip instrument, for example, in regard to a pair of tweezers, the legs thereof, the gripping portion, is of rectangular cross-section, whereas in the case of a round grip instrument the gripping portion is of a semicircular configuration.
In the development of surgical instruments, in particular for microsurgical purposes, there is the requirement that they should be continuously refined from the ergonomic point of view; the aim is to the effect of relieving the load on the hand of the operator while working, and increasing the level of operating comfort. For that purpose, for example in relation to flat grip instruments, the gripping portions were provided at their outside surface or surfaces with gripping surfaces which extend in the longitudinal direction of the instrument and the length of which is determined from variations in spacing, arising out of the operation technique, in respect of the hand of the surgeon relative to the area of operation. To provide for safe and secure handling of the instruments, the gripping surfaces, which in the case of flat grip instruments extend generally over the entire width of the gripping portion while in the case of a round grip instrument they extend on the circumferential surface thereof, have different roughening configurations in the form of holes or grooves which extend transversely with respect to the longitudinal axis of the gripping portions and which are produced by a cutting machining operation; in that case a finger pad on the hand of the user can bear against the grooves while using the instrument.
Particularly in relation to round grip instruments, it is known for the circumference thereof to be provided with mutually crossing grooves so as to produce square or rectangular raised surface portions, depending on the respective groove spacing used.
With gripping surface configurations of that kind, an equilibrium position was produced in the hand of the surgeon by virtue of a particular design configuration of the instruments, while the instrument also made it possible to go easy on the hand muscle strength of the operator by virtue of a reduction in weight and possibly with use-specific fine tuning of the pressure of spring elements. The applicants developed microsurgical instruments of that kind, which afford a high level of operating comfort, and such instruments are described as state of the art in the applicants' sales publications which are available to the public.
In relation to operations of medium and prolonged duration, in particular operations of microsurgical nature, an equilibrium or balance position, a low weight and spring pressures which are set to a minimum value, as far as the inventors are aware, are not crucial on their own in regard to reducing fatigue phenomena in respect of the hand of a surgeon and postponing the occurrence thereof, by virtue of a suitable reduction in the muscle force which is thereby otherwise required.
On the contrary, the extent and the time of occurrence of fatigue phenomena are also determined by the level of the local compression loading on the finger pads and in relation thereof a more or less pronounced level of pressure sensitivity, which are not to be eliminated in regard to instruments of the above-described kind, by very fine mechanical processing such as rounding, polishing and coating of the grooves and raised surface portions, and by wearing surgical gloves.